Nozzles employed for misting fluids with a gas are well-known. Typically, a liquid is directed into a central bore of the nozzle which directs a high-velocity gas. In some nozzles, the velocity and pressure of the gas are increased in a narrowed throat area of the bore which causes the atomization of the fluid into small droplets as the gas travels through the nozzle. To aid atomization and provide an unobstructed flow path for the gas, the fluid is usually injected into the gas stream through an aperture in the bore wall so that the two different fluid streams impinge at a 90-degree angle. Nozzles of the above-described type require high-pressure spraying of the liquid and the gas, which is undesirable. Another problem with the prior art mixing nozzles is that the liquid and gas must be sprayed through fine holes of a small diameter which can easily clog or wear away.
The use of water for a spray for fire extinguishment is well-known. Liquid-only, waterspray nozzles for fire extinguishment create water droplets by deflecting the water flow just ahead of the spouting aperture. The droplet's size is relatively large and a desirable fine water mist cannot be achieved. There is therefore a need in the art for a low-pressure, reliable liquid/gas mixing nozzle, and one which is effective for fire extinguishment.